November 2013 IST blackwood tender results

The November Island Specialty Timbers (IST) tender results provided some mixed results for blackwood. There were three blackwood logs up for tender; two small and one medium size log; all plain grain with some negative quality issues.

Only the smallest log (3.5m length 0.71 m3 volume) sold, but it achieved the very good price of $500 per cubic metre despite the small size and quality issues.

The very good price for a pretty ordinary log is the good news.

The uncertainty comes from the lack of demand for the other two larger blackwood logs. These logs together with a feature-grain eucalypt log were the only logs unsold from the parcel of 22 lots.

So has anyone measured some growth rates for managed blackwoods in Australia on a good block like ours? I think we’re seeing DBH/annum of around 3cm for some of the silver wattles at ten years old. There’s some 60cm silver wattles on the block looking healthy ie not riddled with borer following water stress as is often seen with this species in Vic. An interesting observation is what age they will live to. David Holmgren told me about some dealbata in Tasmania that were huge and which lived for many decades. On my sister’s block in the Yarra Ranges (wet, good soil, a bit higher than us) as unmanaged trees they seem to cark it around 30-35 at 40-50cm DBH. I’ll start measuring the blackwoods and I’ll have a look at the windthrow growth rings.

Hi David,
Blackwood and silver wattle are generally quite different. In most cases I’ve seen silver wattle are much quicker growing. I’ve seen silver wattle get to 50-60cm in 15-20 years. Silver wattles biggest problem is fireblight which is an insect that goes plague every 10 years or so and strips the leaves off making the trees look like they have been in a fire – hence the name. The trees generally die from the attack. Young trees and old are attacked. There’s a plague of it at the moment in northern Tasmania. Hence no one wants to plant a crop that may not make it to market. Otherwise it is good timber.

The biggest silvers I’ve seen were in the upper Mersey river in the mountains. 80 cm dbh and 40 metres tall. Absolute monsters! How old? Hard to guess but I reckon in the mountains they might live for 60 – 80 years; maybe even up to 100 years.

As for blackwoods on a site like yours, have you looked at the annual rings on your downers? Down by the creek on good soil I’d guess you should average 2.0 cm per year with the odd rogue doing better than that. Away from the creek they might be a bit slower. But I’m guessing. Nothing like time and a tape measure:)

Fireblight is a potential concern in Vic. Some areas of prolific regrowth of silver and black wattle did get a whack after the 2009 fires. While looking at properties before we bought our block I saw a number of properties that had areas of very high stem densities of young regen silver wattle where paddocks hadn’t been grazed for a while. None of them were affected by fireblight. But not to say they won’t be hit down the track.

Perhaps mixing up the species a bit may help but this does complicate management. Having worked in finance and done a lot of investing over the years I like the idea of a portfolio approach to tree growing as a way to minimise the impact of pests and disease.

Hi Stu,
Perhaps optimistic in terms of volume, but I think conservative on the price. Depends whether you are an optimist or a pessimist. I would be happy to put a ±25% variance on that value estimate, given all of the variables and unknowns involved.

The New Zealanders will soon find out the value per hectare of a well managed blackwood plantation, and I am definitely optimistic.